Bio Review


I. Vocab
II. Summary
III. Links and Videos


T046406A.gif
An ionic bond

I. Vocab

Chlorine_gas.jpg
Chlorine Gas

Matter - Anything that takes up space and has mass.

Element - Any substance that cannot be broken down into any other substance.

Periodic_Table_of_Elements
Periodic Table of Elements

Compound - A substance consisting of two or more elements in a fixed ratio.

Trace Elements - An element indispensable for life but required in extremely minute amounts.

Atom - The smallest unit of matter that retains the properties of an element.

Neutron - An electronically neutral particle (a particle having no electrical charge), found in the nucleus of an atom.

Proton - A subatomic particle with a single positive electrical charge, found in the nucleus of an atom.

Electrons - A subatomic particle with a single negative charge - one or more electrons move around the nucleus of an atom.

Atomic Nucleus - An atom's central core, containing protons and neutrons.

Dalton - A measure of mass for atoms and subatomic particles.

Atomic Number - The number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol.

Mass_and_atomic_number

Mass Number - The sum of the number of protons and neutrons in an atom's nucleus.

Atomic Weight - The total atomic mass, which is the mass in grams of one mole of the atom.

Isotope - One of several atomic forms of an element, each containing a different number of neutrons and thus differing in atomic mass.

Radioactive Isotope - An isotope, an atomic form of a chemical element, that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy.

radioactive_isotopes.jpg
Radioactive isotope injection

Energy - The capacity to do work (to move matter against an opposing force).

Potential Energy - The energy stored by matter as a result of its location or spatial arrangement.

Energy Level - The different states of PE for electrons in an atom.

Electron Shell - An energy level representing the distance of an electron from the nucleus of an atom.

Valence Electron - Electrons in the outermost electron shell.

Valence Shell - The outermost electron shell of an atom, containing the Valence electrons involved the chemical reactions of that atom.

Orbital - The path an electron follows.

Chemical Bond - The sharing or transfer of Valence electrons.

Covalent Bond - The sharing of a pair of Valence electrons.

covalent_bonding.gif
A covalent bond

Molecule - Two or more atoms held together by covalent bonds.

Polar_water_molecule.jpg
A water molecule

Structural Formula - A type of molecular notation in which the constituent are joined by lines representing covalent bonds.

Molecular Formula - A type of molecular notation indicating only the quantity of the constituent atoms.

Double Covalent Bond - A type of covalent bond in which two atoms share two pairs of electrons; symbolized by a pair of lines between the bonded atoms.

Valence - The bonding capacity of an atom, generally equal to the number of unpaired electrons in the atom's outer shell.

Electronegativity - The attraction of an atom for the electrons of a covalent bond.

Non-polar Covalent Bond - A type of covalent bond in which the electrons are shared equally between two atoms of similar electronegativity.

Polar Covalent Bond - A type of covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

Ion - An atom that has gained or lost electrons, thus acquiring a charge.

Cation - An ion with a positive charge, produced by the loss of one or more electrons.

Anion - A negatively charged ion.

Ionic Bond - A chemical bond resulting from the attraction between oppositely charged atoms.

Ionic Compounds - Compounds resulting from the formation of ionic bonds.

Salts - see Ionic Compounds

van der Waals Interactions - Weak attractions between molecules or parts of molecules that are brought about by localized charge fluctuations.

Reactants - A starting material in a chemical reaction.

Products - An ending material in a chemical reaction.

Chemical Equilibrium - In a reversible chemical reaction, the point at which the rate of the forward reaction equals the rate of the reverse reaction.


II. Summary of Important Concepts

1. Matter consists of chemical elements in pure form and in combinations called compounds.
2. Life requires about 25 chemical elements.
3. Atomic structure determines the behavior of an element.
4. Atoms combine by chemical bonding to form molecules.
5. Weak chemical bonds play important roles in the chemistry of life.
6. A molecule's biological function is related to its shape.
7. Chemical reactions make and break chemical bonds.

III. Links and Videos

Bio Review Website

All information courtesy of the Biology textbook.